We introduce a new approach to hot electron effects in Si-MOSFETs, based on a mixture of evolutionary optimization algorithms and Monte Carlo technique. The Evolutionary Algorithm searchs for electron distributions which fit a given goal, for example a measured substrate current and in this way can calculate backwards electron distributions from measurement results. The search of the Evolutionary Algorithm is directed toward physically correct distributions by help of a Monte Carlo like mutation operator. Results for bulk-Si demonstrate the correctness of the physical model in the Monte Carlo like mutation operator and the backward calculation ability of the Evolutionary Algorithm. First results for Si-MOSFETs are qualitatively comparable to results of a Full Band Monte Carlo simulation.